Help with using ISP name for email

[Jason Ish <jbi130@mail.usask.ca>]

I connect to the internet using my school PPP account which gives me a
user name not very close to my real name and chose to use my first name to
logon to my personal linux box.  I would like to send email but have it
come from my school email name and not my localhost name.  I have already
managed (using smail/mailx) to have the @hostname field changed but mail
still comes from jason rather than jbi130 (my email username).  

To fix this I have starting using pine, I start it using sudo as user
jbi130 on my home system but these becomes a pain (as far as file
permissions) are concerned when add folders and deleting stuff and so on.

Is there a better way to go about this.  I use fetchmail ro retrieve from
my POP3 server but I don't think this has any effect on the sending of the
mail.
Would a better solution maybe to sart using mh and exmh?

Thanks for any help.
Jason Ish
jbi130@mail.usask.ca